Declare Content Provider and allow access from another app.

AndroidManifest_PROVIDER.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.android.sunshine.app">
    <application>
        <activity>...</activity>
        <provider
            android:name=".data.WeatherProvider"
            android:authorities="com.example.android.sunshine.app"
            android:enabled="true"
            android:exported="true"
            android:permission="com.myapp.OhhhhDiosito">
        </provider>
    </application>
    <permission
        android:name="com.myapp.OhhhhDiosito"
        android:label="ohhh diosito"
        android:protectionLevel="dangerous">
    </permission>
</manifest>